Snapshot v6.2.3 regression

.gitignore

@@ -8,3 +8,4 @@ TODO
 .vscode
 build
 npm-shrinkwrap.json.bak
+test/testdb

lib/database.js

@@ -30,11 +30,14 @@ Database.prototype.initialize = function(callback) {
     if (err) {
       return callback(err);
     }
-    levelup(
-      self.options.db || encode(cachedown(directory, filedown).maxSize(100)),
-      { valueEncoding: "json" },
-      finishInitializing
-    );
+    const levelupOptions = { valueEncoding: "json" };
+    if (self.options.db) {
+      const store = self.options.db;
+      levelup(store, levelupOptions, finishInitializing);
+    } else {
+      const store = encode(cachedown(directory, filedown).maxSize(100), levelupOptions);
+      levelup(store, {}, finishInitializing);
+    }
   });
 
   function finishInitializing(err, db) {